This invention relates to the manufacture of readily-releasable adhesive material which is packaged and handled on a release coated web carrier, e.g. a paper carrier.
It is old to coat pressure sensitive adhesive on a substrate for eventual transfer to another substrate such as label stock or the like. A preferred procedure has been to place the coating on a substrate which is itself coated with a different release coating on each side of the substrate. The idea is to put the adhesive on a relatively difficult-to-release coat, yet a function release surface, but to have the back side of the substrate coated with a very easy-to-release coat so that when the adhesive-coated substrate is eventually unwound for use, there will be little release of the back-coating pulling the adhesive away from the surface on which it has been coated. Maintaining proper quality control of the two different release coatings has been a substantial problem, and it has been recognized as a problem by most manufacturers because failure inevitably results in defective rolls and, if such rolls are not intercepted, complaints from those who most use the rolls in subsequent processes to make products which incorporate the adhesive.
The work associated with the invention-to-be described below has allowed the inventor to have a further understanding of additional problems in the prior art which were not necessarily known to those encountering the problems. Such problems will be discussed below.